Starting with the behavior of the system directs one’s thoughts to dynamic, not static, analysis—not only to “What’s wrong?” but also to “How did we get there?” “What other behavior modes are possible?” “If we don’t change direction, where are we going to end up?” And looking to the strengths of the system, one can ask “What’s working well here?” S

The … goal of all theory is to make the … basic elements as simple and as few as possible without having to surrender the adequate representation of … experience. —Albert Einstein,1 physicist

Reinforcing feedback loops are self-enhancing, leading to exponential growth or to runaway collapses over time. They are found whenever a stock has the capacity to reinforce or reproduce itself.

It is called a reinforcing feedback loop, and will be noted with an R in the diagrams. It generates more input to a stock the more that is already there (and less input the less that is already there).

Balancing feedback loops are equilibrating or goal-seeking structures in systems and are both sources of stability and sources of resistance to change.

Remember—all system diagrams are simplifications of the real world.

A feedback loop is a closed chain of causal connections from a stock, through a set of decisions or rules or physical laws or actions that are dependent on the level of the stock, and back again through a flow to change the stock.

It is the consistent behavior pattern over a long period of time that is the first hint of the existence of a feedback loop.

That means system thinkers see the world as a collection of “feedback processes.”